--- /dev/null
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build amd64,linux
+// +build gc
+
+package unix
+
+import "syscall"
+
+//go:noescape
+func gettimeofday(tv *Timeval) (err syscall.Errno)